JP7043991B2 - Monitoring terminal - Google Patents

Description

The present invention relates to a technique for monitoring environmental information.

It is important from the viewpoint of disaster prevention and citizen services to monitor and provide environmental information related to the living environment of residents, such as the inundation situation due to guerrilla rainstorms in urban areas and the temperature distribution in specific areas as a preventive measure for heat stroke. It has become so.

Therefore, as a monitoring device and a monitoring system for environmental information, for example, a liquid level sensor device for detecting the liquid level of inundation due to flood damage and a host computer for transmitting the liquid level information acquired by this liquid level sensor device are used. A detection system having a detection system has been proposed (Patent Document 1).

Since the above monitoring device can operate on a battery due to its low power consumption, the frequency of battery replacement can be reduced, and when a solar cell is used, it can be used for a long period of time for maintenance. The cost can be reduced.

Japanese Unexamined Patent Publication No. 2007-218740 Japanese Unexamined Patent Publication No. 2016-11557 Japanese Unexamined Patent Publication No. 2012-29020

For real-time monitoring of environmental information, it is necessary to install a measurement monitoring device, but the above-mentioned conventional monitoring device and monitoring system require electrical work such as power lead-in work and civil engineering work, and the battery It is also necessary to reduce the frequency of replacement.

The purpose of using the measurement / communication device is disaster prevention and citizen services, and it is more closely related to the lives of residents. In addition to the viewpoint of maintenance cost, the measurement device is required to have high reliability and maintenance. There is a demand for easy equipment. Ease of maintenance such as battery replacement and sensor inspection and repair is important for the normal operation of monitoring devices and systems.

In view of the above circumstances, it is an object of the present invention to improve maintainability while reducing maintenance costs in monitoring environmental information.

One aspect of the present invention is a monitoring terminal, which is a terminal body unit that is erected at a monitoring place for environmental information, a measurement unit that detects the environmental information that can be attached to the terminal body unit, and the terminal body unit. A communication unit that transmits the detected environmental information to the outside and a power supply unit that supplies power to the measurement unit and the communication unit are provided, and the power supply unit supplies the power. It includes a secondary battery, a solar panel for charging the secondary battery, and a primary battery used for charging the secondary battery when the charging by the solar panel is insufficient.

One aspect of the present invention further includes a control unit that performs measurement processing of the environmental information or changes in the measurement cycle or transmission cycle in response to a command from a higher-level server via a mobile phone network or a low-power wide area communication network.

One aspect of the present invention further includes a control unit that changes the measurement cycle or transmission cycle of the environmental information based on the environmental information detected by the measurement unit.

In one aspect of the present invention, the measuring unit measures the water level as the environmental information by the capacitance method.

In one aspect of the present invention, the outer cylinder of the measuring unit is used as one of the electrodes used for the measurement.

According to the above invention, it is possible to reduce the maintenance cost and improve the maintainability in monitoring the environmental information.

The schematic block diagram of the monitoring terminal which is one aspect of this invention. The block configuration diagram of the monitoring terminal. The block block diagram of the measurement part of the monitoring terminal. (A) is a characteristic diagram showing the relationship between the capacitance and the measured current value, and (b) is a characteristic diagram showing the relationship between the capacitance and the inundation depth. The flowchart of the measurement cycle change of the said monitoring terminal by a command from a server. The flowchart of the automatic measurement of the monitoring terminal.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The monitoring terminal 1 exemplified in FIG. 1 acquires environmental information of a predetermined place where the monitoring terminal 1 is installed and transmits it to the outside. The monitoring terminal 1 periodically transmits the environmental information of the monitoring location 10 detected by the measurement unit 3 to the upper server 6. Further, the environment information is transmitted to the server 6 based on the request from the server 6. Further, if the environmental information (for example, rainfall intensity) indicates predetermined environmental information (for example, an alarm threshold value), the environmental information is transmitted to the server 6.

The environmental information data acquired by the monitoring terminal 1 is managed on the cloud and can be remotely monitored. Further, the data of the environmental information is mapped to the map information based on the position information, and it is possible to visually grasp the environmental condition such as the rainfall intensity condition. For example, rainfall intensity data is collected on the cloud, and the data can be browsed ubiquitously. Therefore, the operation / failure information and the environment information of the monitoring terminal 1 can be displayed on the graphic user interface. In addition, the rainfall intensity at the measurement point can be color-coded and displayed as a symbol or mesh on the user's terminal.

When the server 6 receives the environmental information from the monitoring terminal 1, for example, the server 6 outputs map information to which the environmental information is added. The server 6 is arranged, for example, at a base of an information providing service operated by a local government or a private company. Then, a user who uses this information providing service can browse the map information in real time by accessing the homepage of the information providing service from a display terminal 7 such as a smartphone, a tablet, or a personal computer.

(Example of mode of monitoring terminal 1)
The monitoring terminal 1 includes a terminal main body unit 2, a measurement unit 3, a communication unit 4, and a power supply unit 11 and a CPU unit 12 shown in FIG. 2.

The terminal body 2 is installed at a monitoring location 10 where environmental information is monitored. The terminal body 2 is formed into an appropriate cylinder according to the monitoring location 10. As the constituent material of the terminal main body 2, stainless steel having excellent rust resistance is preferable, but a steel material having a rust-preventive treatment on the surface is applied. Further, a material other than the steel material such as concrete or ceramic is applied according to the strength required for the terminal main body 2. Further, an information display unit 5 is provided on the outer surface of the terminal body unit 2. The information display unit 5 can display, for example, environmental information or an alarm based on this environmental information.

The measurement unit 3 detects the environmental information of the monitoring location 10. The environmental information includes, for example, meteorological information such as temperature, humidity, atmospheric pressure, rainfall intensity, and solar radiation dose, special environmental information such as radiation dose and radioactivity, and inundation depth (water level) when the monitoring location 10 is submerged. Either or a combination thereof may be mentioned. A well-known measuring instrument may be applied as the means for detecting the environmental information. For example, when the rainfall intensity sensor is applied to the measuring unit 3, it is arranged on the upper end side of the monitoring terminal 1. The rainfall intensity sensor is a water droplet counting type sensor that counts the rainfall captured from the water receiving port at the upper end of the sensor body of the measuring unit 3 by dropping it one by one. It is also possible to measure the intensity instantaneously.

Further, the measurement unit 3 is periodically activated to detect the environmental information, and then goes into a sleep state, and can shift to the standby mode with the minimum power. The environmental information is stored in the storage unit of the measurement unit 3 and transmitted to the server 6 via the mobile communication network.

While the communication unit 4 can be attached to the terminal main body unit 2, the communication unit 4 transmits the environmental information detected by the measurement unit 3 to the server 6. As the communication unit 4, for example, the communication unit interface disclosed in Patent Documents 2 and 3 is applied.

The power supply unit 11 supplies electric power to the measurement unit 3, the communication unit 4, and the CPU unit 12.

The CPU unit 12 functions as a control unit that controls the operation of the measurement unit 3 based on the flowcharts of FIGS. 5 and 6.

(Example of mode of power supply unit 11)
The monitoring terminal 1 adopts an energy harvest method using a solar panel 21 and includes a primary battery 23 as a backup thereof. In particular, an operation method (for example, Patent Documents 2 and 3) that can reduce energy consumption by intermittently operating with the secondary battery 20 with low power consumption is adopted.

That is, as shown in FIG. 2, the power supply unit 11 includes a secondary battery 20, a photovoltaic panel 21, a photovoltaic circuit 22, a primary battery 23, a voltage monitoring circuit 24, a battery charger 25, and a power supply circuit 26. Makes two power supply systems.

The first power supply system supplies the electric energy obtained by the solar panel 21 to the battery charger 25 as electric power to charge the secondary battery 20.

The second power supply system cannot be charged by the solar panel 21 due to rainy weather or the like, and further, when the electric energy capacity of the secondary battery 20 decreases due to the frequency of use of the monitoring terminal 1, the electric energy A large-capacity primary battery 23 is used to supplement the energy. Normally, the secondary battery 20 is trickle-charged by the solar panel 21 via the photovoltaic circuit 22 so that the secondary battery 20 can be used in a fully charged state at all times.

Then, when the monitoring terminal 1 starts and performs measurement operation, the output voltage of the primary battery 23 is detected by the voltage monitoring circuit 24 and supplied to the CPU unit 12, and then the communication unit 4 sends the battery to the outside (for example, the server 6). It is transmitted as the remaining voltage information.

The secondary battery 20 is charged by the battery charger 25. The secondary battery 20 automatically supplies power to the load when the input voltage drops below the float voltage.

Specifically, power is supplied to the loads of the measuring unit 3, the communication unit 4, the CPU unit 12, and the like via the buck-boost converter of the power supply circuit 26. More specifically, even if the current consumption is consumed by the inundation monitoring function in rainy weather, charging by solar power generation cannot be expected because it is rainy weather, but the minimum necessary power energy is supplied to the secondary battery 20. For example, even when the float voltage of the secondary battery 20 drops from 4.2V to 2.8V, the buck-boost converter of the power supply circuit 26 causes 3.3V for an input operating range of, for example, 1.8V to 6V. Output voltage can be generated.

A lithium battery is exemplified as the secondary battery 20. As for the capacity of the secondary battery 20, a sufficient energy capacity is secured in consideration of the relationship between the charging by the solar panel 21 and the inundation state during the rainy weather operation and the discharge during the inundation operation.

Further, as a backup, the secondary battery 20 has a reduced battery capacity and can be charged by the large capacity primary battery 23 via the battery charger 25 in relation to the energy capacity of the primary battery 23. good. Therefore, a diode having a low drop voltage (for example, a Schottky barrier die) is mounted on the output side of the photovoltaic circuit 22 to which the battery charger 25 is connected and the primary battery 23.

The battery charger 25 performs a charging operation so that the secondary battery 20 can reach the float voltage and maintain a full charge. Examples of the charging method of the secondary battery 20 include a float charging method and a trickle charging method. In the float charging method, when the battery is fully charged, the current passes through the bypass circuit in the charger to eliminate the load on the battery. The trickle charge method always maintains a fully charged state by constantly passing a small current in order to compensate for the capacity loss due to discharge.

(Example of a mode of the CPU unit 12)
The CPU unit 12 performs intermittent operations (sleep state and wake-up state) based on a preset cycle in order to perform low power consumption operation, and operates with low power consumption. In particular, the CPU unit 12 suppresses the consumption of current consumption during sleep, calculates the inundation amount (inundation depth) from the value of the voltage supplied from the measurement unit 3 at startup, and performs necessary processing. , Information is transmitted to the outside (for example, server 6) via the communication unit 4. Further, the output voltage of the primary battery 23 supplied from the voltage monitoring circuit 24 of the power supply unit 11 is transmitted to the outside as the remaining amount information of the battery voltage.

(Example of embodiment of measurement unit 3)
The measuring unit 3 adopts a capacitance method as a method for measuring inundation. In the capacitance method, a pair of insulated electrodes are immersed in water, and the water level is detected from the capacitance between the electrodes. Since this measurement method does not cause corrosion of the electrodes, it is effective from the viewpoint of reduction of maintenance cost and maintainability as compared with the electric resistance method in which corrosion of the electrodes is likely to occur.

The principle of water level measurement based on the capacitance method will be described below.

When an AC signal source with a frequency of f [Hz] is connected to a capacitor with a capacitance of C [F], the reactance Xc "Ω" of the capacitor is indicated by Xc = 1 / (2πfC) (hereinafter, equation (1)). Will be.

The current i [A] flowing through the capacitor of the capacitance C [F] is represented by i = v / Xc = v2πfC (hereinafter, equation (2)) when the voltage of the AC signal source is v [V]. ..

A current is generated from a transmitter, which is an AC signal source, through a capacitor having an unknown capacitance C. If the frequency f [Hz] and the voltage v [V] of the AC signal output from the transmitter are constant, a current proportional to the capacitance C flows according to the equation (2). When this current value is converted into a voltage value and further A / D conversion (analog-digital conversion) is performed, the digital value can obtain a numerical value related to the capacitance C. If the relationship between the digital value, the capacitance C, and the water level is made into a table, the water level can be measured from the digital value. For example, in the case of an AC signal source of 1 KHz and 1 MHz, if the current i flowing through the detection unit 30 of the measurement unit 3 is measured and the current function and the capacitance C are calculated by the CPU unit 12, the relationship with the water depth can be obtained. It is possible to derive.

A specific embodiment of the measuring unit 3 and an operation example thereof will be described with reference to FIG.

The measurement unit 3 includes a detection unit 30, an oscillation circuit 31, a drive circuit 32, a conversion circuit 33, and a filter amplification circuit 34.

The detection unit 30 includes a pair of insulating electrodes as a conductor used for measuring the capacitance. The outer cylinder of the measuring unit 3 is applied to one of the pair of insulating electrodes.

The drive circuit 32 receives a control signal from the CPU unit 12 and drives the detection unit 30 activated by the signal output from the oscillation circuit 31.

The conversion circuit 33 converts the value of the current detected by the capacitance coupling between the insulating electrodes of the detection unit 30 into the value of the voltage, and then uses the filter amplifier circuit 34 in order to obtain a predetermined signal source. It is output to the CPU unit 12 via. In the CPU unit 12, the signal level is converted by the A / D conversion unit. The relationship between the current i and the capacitance C is expressed as a function of the capacitance represented by the above equation (2).

FIG. 4A shows the relationship between the capacitance and the measured current value, and FIG. 4B shows the relationship between the capacitance and the inundation depth. By measuring the relationship between the capacitance and the inundation length in advance and creating a table based on such a linear relationship between the two, the relationship between the capacitance and the inundation depth can be directly grasped.

An operation example of the monitoring terminal 1 will be described below.

(Operation example 1)
The flowchart of FIG. 5 describes a process of changing the measurement cycle of the monitoring terminal 1 by a command from the server 6 (operation example 1), or a process of operating by starting by an internal timer for regular cycle activation set by the monitoring terminal 1 itself. It was done. The monitoring terminal 1 uses an intermittent operation that repeats regular cycle startup and sleep, and a communication downlink during sleep, in order to perform low power consumption operation, and is activated based on a command from the server 6 to change the measurement cycle. Perform low power consumption operation that makes you want to. For example, normally, a communication cycle once a day is set in advance for checking the soundness of the monitoring terminal 1, but when it rains or there is a possibility of flooding, the measurement cycle is set according to the degree of flooding. For example, it is changed to 1-hour cycle measurement or 10-minute cycle measurement. The fixed cycle operation and the cycle change process of the operation example 1 are executed in the following steps S101 to S112.

S101: The CPU unit 12 of the monitoring terminal 1 determines whether or not the command from the server 6 via the communication unit 4 is a command for changing the measurement cycle.

S102: When the command from the server 6 is "change of measurement cycle", the CPU unit 12 changes the measurement cycle, and at the timing for knowing the inundation depth from the health check cycle of the monitoring terminal 1. , The next start-up time in the internal timer of the monitoring terminal 1 is changed.

S103: When the change of the activation cycle is completed, the CPU unit 12 goes into a sleep state by the sleep process.

S104: The CPU unit 12 shifts to the process of the "measurement process" of S105 when the start condition is the "constant cycle measurement process" activated by the internal timer.

S105: The CPU unit 12 drives the drive circuit 32 of the measurement unit 3 to generate a voltage, obtains a predetermined signal corresponding to the capacitance from the detection unit 30 by the filter amplification circuit 34 path, and performs a conversion process. The inundation depth is measured based on the capacitance.

S106: When the measurement cycle and the transmission cycle are set to be the same, the measured inundation depth value is transmitted to the server 6 via the communication unit 4. For example, in the case of a measurement cycle of 10 minutes and a transmission cycle of 1 hour, the transmission process is performed by collectively transmitting the recorded values every 10 minutes in 1-hour units. If it is a recording cycle and not a transmission cycle, it is recorded in the internal memory of the CPU unit 12 after the measurement process of S105, but the transmission process in S106 is not executed. It shifts to the sleep of S107.

S107: When the transmission cycle is not set, after recording by the measurement process, or when the transmission cycle is set, the CPU unit 12 completes the transmission of the inundation depth value and the recorded untransmitted inundation depth value. Go to sleep.

S108: If the command from the server 6 is "current value request", the process proceeds to "measurement processing" in S109.

S109: When the measuring unit 3 receives the "current value request" from the CPU unit 12, the inundation depth based on the capacitance is obtained in order to obtain the inundation depth at the time of the current value request, as in the measurement process of S105. Perform the measurement.

S110: The current value of the measured inundation depth is transmitted to the server 6 via the communication unit 4.

S111: When the transmission of the current value is completed, the CPU unit 12 goes to sleep.

S112: If the command from the server 6 is not a request for any of "cycle change", "constant cycle measurement processing", and "current value", another processing is performed.

(Operation example 2)
The flowchart of FIG. 6 describes an operation method when only an uplink is prepared as a communication line with the server. For example, the mobile phone network has an uplink and a downlink, but if only an uplink is prepared in an LPWA (Low Power Wide Area), etc., it operates because there is no downlink. Parameters such as measurement cycle and transmission cycle cannot be changed by the downlink as in Example 1. Therefore, in the operation example 2, the monitoring terminal 1 autonomously changes the parameters of the measurement cycle and the transmission cycle.

In the operation example 2, the monitoring terminal 1 is started by the internal timer (hereinafter referred to as timer start) as a fixed cycle start, and only the soundness check is performed. Examples of this sanity check include a calibration check of the monitoring terminal 1, a transmission / reception check, an internal timer operation check, and the like.

The measurement is started based on the threshold value of the monitoring target (analog current value (AI value) detected by the detection unit 30) (hereinafter referred to as AI start). By starting this AI, a fixed cycle measurement process is executed. A plurality of AI value threshold values are set, and the measurement cycle and transmission cycle can be changed step by step. For example, the measurement cycle or the transmission cycle is changed according to the environment. Explaining a specific operation example, when the monitoring terminal 1 detects an inundation of 1 cm, it executes measurement and transmission of the water level on a schedule of a measurement cycle of 10 minutes and a transmission cycle of 1 hour. Then, when the rainfall becomes heavy and inundation of 3 cm is detected, the schedule is changed to a measurement cycle of 1 minute and a transmission cycle of 10 minutes. After that, when the inundation is less than 3 cm, the measurement cycle is changed from 1 minute to the measurement cycle of 10 minutes, and when the inundation is less than 1 cm, the normal sanity check cycle, for example, a 24-hour cycle is changed.

In the activation method using the internal timer, the activation cycle is determined by setting the next activation time at the time of activation. For example, when setting the sanity check cycle in the internal timer, when the same time on the next day is set from the time on a predetermined date, the activation cycle of "health check of monitoring terminal 1" is set to a 24-hour cycle. Will be done.

As an operation example 2, a transmission processing example in which the periodic cycle can be changed only by the processing system of the monitoring terminal 1 itself is executed in the following steps S201 to S211.

S201: The CPU unit 12 of the monitoring terminal 1 determines whether the activation factor is either "timer activation" or "AI activation". When the activation factor is "AI activation", since it is an interrupt exceeding the threshold value of the inundation value which is the preset AI value, the process of starting the fixed cycle measurement, the "fixed cycle measurement start process" of S210 Transition. If the activation factor is not the "AI activation" interrupt, the "timer activation" interrupt causes the process to shift to the "measurement process" of S203 to S207 or the "sanity check" process of S208 and S209.

S202: If the mode of the monitoring terminal 1 is "timer activation" in which the measurement flag for constant cycle measurement is set in S210 at the previous timing, it is "measurement processing", so that it is "measurement processing" in S203. Move to the process of. On the other hand, if the mode measurement flag is not set for "timer activation", it is a "sanity check", so the process proceeds to the "sanity check" process of S208.

S203: If the fixed cycle measurement is started and the measurement flag is set to "timer start", the measurement process is executed. That is, the measuring unit 3 measures the inundation depth based on the capacitance at the time when the timer is started at a fixed cycle.

S204: The current value of the measured inundation depth is compared with the previous value. When a predetermined change (for example, an increase in the inundation depth of a certain level or more) is not observed between the current value of the inundation depth and the previous value, the monitoring terminal 1 goes into a sleep state.

S205: When the above change is observed, it is transmitted to the server 6 that the change in the inundation depth above a certain level is observed. For example, when a change amount of 0.5 cm or more is confirmed, an increasing tendency is transmitted, and if the change amount is less than 0.5 cm, it is considered that the change amount is maintained and the transmission may be omitted. By omitting it, communication traffic will be reduced, it will contribute to lower power consumption, and it is expected to be effective in extending battery life.

S206: After the comparison of S204 is executed and it is recognized that the flooding level has been relaxed and the transmission process is completed, when the relaxation amount becomes less than the preset relaxation value and the measurement is terminated, the process shifts to S207. do. If no less than the relaxation value is found, continue the measurement.

S207: In order to stop the measurement, the measurement flag is reset and the timer for the constant cycle measurement is also initialized (returning to the sanity check cycle) to end the measurement. After that, the process shifts to the sleep process of S211.

S208: The CPU unit 12 periodically executes the sanity check of the measurement unit 3 based on the internal timer.

S209: The result of the sanity check is transmitted to the server 6 via the communication unit 4.

S210: Since the threshold value set in advance has been exceeded by "AI activation", the measurement flag is set and the timer value for constant cycle measurement is set as the measurement is performed from this. In the internal timer, a sanity check cycle or a cycle for constant cycle measurement is set. For example, when the sanity check cycle is a 24-hour cycle in the internal timer, for example, 10 minutes from the time when the "measurement mode" is set due to the "AI start" due to the AI value exceeding the preset AI value due to flooding in rainy weather. Measure the inundation depth every time. This measured inundation depth value is the relationship between the preset measurement cycle and the transmission cycle to the server. In the case of measurement and transmission processing in the same cycle, in the case of collective transmission, etc., the communication unit is used for each measurement. It is transmitted to the server 6 via 4.

S211: When the soundness check or the measurement is completed, the monitoring terminal 1 goes to sleep.

After that, when the time set by the internal timer of the monitoring terminal 1 comes, the activation interruption of S201 occurs. Then, when it is confirmed in S202 that the mode is in the measurement mode, the process proceeds to the measurement process in S203. On the other hand, if it is determined that the activation factor is not the measurement mode, the process shifts to the sanity check process of S208, the above-mentioned periodic sanity check is executed, and then the sleep state of S211 is entered.

(Effect of this embodiment)
According to the above monitoring terminal 1, since the power supply is realized by the energy harvest by the solar panel 21, maintainability such as battery replacement is simplified. Further, when the secondary battery 20 is insufficiently charged by the solar panel 21, the primary battery 23 performs backup charging, so that the maintainability of the monitoring terminal 1 is improved. In particular, maintainability is further improved by monitoring the backup primary battery in the process of sanity check.

Further, the monitoring terminal 1 can voluntarily change the measurement cycle at low cost by communicating with the server 6 via the mobile phone network or the low power wide area communication network.

Since the monitoring terminal 1 can change the measurement cycle by a command from the server 6 via the downlink, flood monitoring can be performed at an arbitrary cycle.

Further, since the measurement unit 3 can determine the inundation depth by measuring the water level as the environmental information based on the capacitance measurement method, the inundation measurement can be performed more robustly and at a lower cost than the electric resistance measurement method. .. In particular, by using the outer cylinder of the measuring unit 3 as one of the electrodes used for measuring the capacitance, the measurement can be performed at a lower cost.

Furthermore, the linear relationship between the inundation depth and the capacitance allows approximation by two points, offset and gain, and after the process of checking the sanity of the monitoring terminal 1, the table is set in the adjustment / reset process. By updating, the accuracy can be improved.

In Operation Examples 1 and 2, the monitoring location 10 monitors the inundation depth when flooded, but environmental information other than the inundation depth (for example, weather such as temperature, humidity, pressure, rainfall intensity, and amount of solar radiation). Information or special environmental information such as radiation amount and radioactivity) can also be applied as a monitoring target. At that time, the measurement method of the measurement unit 3 is applied according to the monitored environmental information.

1 ... Monitoring terminal 2 ... Terminal body 3 ... Measurement unit, 30 ... Detection unit, 31 ... Oscillation circuit, 32 ... Drive circuit, 33 ... Conversion circuit, 34 ... Filter amplification circuit 4 ... Communication unit 5 ... Information display unit 6 ... Server 7 ... Display terminal 11 ... Power supply unit, 20 ... Secondary battery, 21 ... Solar panel, 22 ... Photoelectric power generation circuit, 23 ... Primary battery, 24 ... Voltage monitoring circuit, 25 ... Battery charger, 26 ... Power supply circuit 12 ... CPU unit (control unit)

Claims (3)

The main body of the terminal installed in the monitoring place for environmental information,
A measurement unit that detects the environmental information that can be attached to the terminal body,
A communication unit that can be attached to the terminal body and transmits the environmental information detected by the measurement unit to the outside.
A power supply unit that supplies electric power to the measurement unit and the communication unit is provided.
The power supply unit
The secondary battery that supplies the power and
The solar panel that charges this secondary battery and
When the charging by the solar panel is insufficient, the primary battery used for charging the secondary battery and the primary battery
Equipped with
The measuring unit measures the water level as the environmental information by the capacitance method.
The outer cylinder of the measuring unit shall be used as one of the electrodes used for the measurement.
A monitoring terminal featuring. Claim 1 is further provided with a control unit that performs the water level measurement processing or the measurement cycle or transmission cycle change according to a command from a higher-level server via a mobile phone network or a low-power wide area communication network. The monitoring terminal described in. The monitoring terminal according to claim 1, further comprising a control unit that changes the measurement cycle or transmission cycle of the water level based on the water level detected by the measurement unit.

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